Harman PM645 User Manual

FEATURES
GENERAL INSTRUCTIONS
MHCC (High-instantaneous Current Capability)
Recent studies have shown that while reproducing dynamic
music signals the instantaneous impedances of nearly all
loud-speakers drop to less than one third of the nominal
ratings. These low instantaneous impedances typically
require 3 to 6 times more current than an 8 Ohm resistive
load. Reduced dynamic range and increased distortion will
result if the amplifier cannot provide these higher currents.
For this reason, the PM645 was designed to provide 35
amperes of instantaneous Current.
E Ultrawide Bandwidth
The bandwidth of this unit is exceptionally wide and inde-
pendent of negative feedback. This improves transient
accuracy and phase linearity.
E Low Negative Feedback
This unit has been designed to have low distortion and wide
bandwidth without high negative feedback. This further
improves its dynamic accuracy.
@ Discrete Component Circuitry
In order to achieve the above goals, all discrete electronic
circuitry has been employed. All available integrated circuits
could not provide this high level of performance.
E Sophisticated Electronic Protection
Harman Kardon engineers developed a unique protection
system that permits high instantaneous current to be driven
into speaker systems but protects the amplifier from short-
circuited or damaged speakers and wires. This protection
system in no way limits amplifier output voltage or current
during music reproduction, and therefore has no negative
effect on sound quality.
BBass Contour
Bass contour is an exclusive Harman Kardon feature which
provides two major benefits: it can equalize and restore the
low frequency response of small loud-speakers, and it can
be used in place of conventional loudness contour. But
unlike conventional bass boost circuits, Harman Kardon's
bass contour also includes a phase correction circuit that
maintains clear, natural sound.
Always Use the Correct AC Voltage
Always connect the power cord to a domestic mains outlet.
Never connect the unit to an outlet supplying a higher
voltage. This may create a fire hazard.
NOTE FOR CUSTOMERS OTHER THAN CANADA
This unit is supplied with a voltage selector enabling
selection between 220V and 240V on the rear panel. If the
selector is not set to the local voltage, set the selector to the
correct voltage with a screwdriver before connecting the
power cord to a mains outlet.
Handle the Power Cord Gently
@Do not disconnect the plug from the AC outlet by pulling
the cord: always pull the plug itself. Pulling the cord may
break the wire.
@ff you do not intend to use your unit for any considerable
length of time, disconnect the plug from the AC outlet.
@Do not place furniture or other heavy objects on the cord,
and avoid dropping heavy objects on it. Also do not make a
knot in the power cord. Not only may the cord be damaged, it
can also cause a short circuit and a consequent fire hazard.
Place of Installation
Place your unit on a firm and level surface. Avoid installing
your unit under the following conditions:
BP Moist or humid places.
Places exposed to direct sunlight or close to heating
equipment.
> Extremely cold locations such as those in the direct draft
from an air conditioner.
Places subject to excessive vibration or dust.
> Poorly ventilated places.
Do not cover the ventilation slots on the top of the unit. This
will cause the temperature inside the unit to rise, which can
eventually effect the reliability of your unit.
Moving the Unit
Before moving the unit, be sure to unplug the power cord
from the AC outlet and disconnect the interconnection
cords to other units.
Do Not Open the Cabinet
To prevent fire or shock hazard, do not tamper with internal
components for inspection or maintenance. Harman
Kardon does not guarantee against performance degrada-
tion resulting from any modification.
If water, a hairpin or wire accidentally enters the unit,
immediately unplug the power cord from the AC outlet to
prevent shock and consult an authorized Harman Kardon
service station. If you use the unit under this condition, it
may cause a fire or shock hazard.
Cleaning
When the unit gets dirty, wipe it with a soft dry cloth. If
necessary, wipe it with a soft cloth dampened with mild
soapy water and then wipe with a dry cloth.
Never use benzine, thinner, alcohol or other volatile agent,
and avoid spraying an insecticide near the unit.

Harman PM645 Specifications

General

Brand	Harman
Model	PM645
Category	Amplifier
Language	English